Question

Surfactant molecules can cluster together as micelles, to be in colloid size. Micelles from only above critical micelle concentration (CMC) and above a certain temperature called kraft temperature. $\Delta H$ of micelle formation can be positive or negative. Which is false about micelle formation?
(A). The hydrophobic part lies towards the interior of micelle.
(B). The hydrophilic part lies towards the surface of the micelle.
(C). $\Delta S$ of micelle formation is positive.
(D). $\Delta S$ of micelle formation is negative

Answer 1

Hint: In general a micelle is an agreement of several surfactant molecules dispersed in a medium like liquid and leads to the formation of the colloidal suspension. According to I.U.P.A.C ( international union of pure and applied chemistry ) micelles are the very minute particles which are capable of forming an equilibrium with the ions or molecules in solution from which they are synthesised.

Complete answer:
Krafft temperature is the temperature required for the solubility of the surfactants to be equal to critical micelle concentration (CMC).
The increase in the length of the chain of a micelle, usually the hydrocarbon chain ( hydrophilic part ) will increase the required krafft temperature as well.
The most common example of micelle is the action of soap or the detergents.
The correct answer is option (C). $\Delta S$ of micelle formation is positive.

Note:
The critical micelle concentration (CMC) having surfactants can act as emulsifiers which helps in the desolation of the un- soluble particles in the liquid medium. Micelles are responsible for the absorption of various fat soluble vitamins, lipids in the human body. Micelles can also be used as an active drug delivery or drug target substrate.